I'm in the process of deciding whether to buy / lease and in doing my math/calculations, there's something I noticed that could potentially impact this.
When you LEASE a plane, that is considered a weekly/monthly expense and is deducted from your taxable income.. In the US, 30%.
Does the purchase price of a new plane get deducted in any way?
The bean counting portion of the manual should explain, but in short, assets (planes) that you buy are depreciated over their "useful life" (determined to be through age 25 by the game) on a straight line basis to its estimated scrap value. The depreciation is recorded as a non cash expense.